diff --git a/app/chain/transfer.py b/app/chain/transfer.py
index f3123695..5a7b40ba 100755
--- a/app/chain/transfer.py
+++ b/app/chain/transfer.py
@@ -799,10 +799,7 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
             return StorageChain().is_bluray_folder(fileitem)
         if not fileitem.extension:
             return False
-        media_exts = (
-            self._media_exts if hasattr(self, "_media_exts") else settings.RMT_MEDIAEXT
-        )
-        return True if f".{fileitem.extension.lower()}" in media_exts else False
+        return True if f".{fileitem.extension.lower()}" in self._media_exts else False
 
     def __is_allowed_file(self, fileitem: FileItem) -> bool:
         """
@@ -1179,8 +1176,6 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
         """
         if not task or not task.transfer_batch_id:
             return
-        if not hasattr(self, "_scrape_batches"):
-            self._scrape_batches = {}
         with job_lock:
             batch = self._scrape_batches.setdefault(
                 task.transfer_batch_id,
@@ -1198,8 +1193,6 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
         """
         if not batch_id:
             return
-        if not hasattr(self, "_scrape_batches"):
-            self._scrape_batches = {}
         with job_lock:
             batch = self._scrape_batches.setdefault(
                 batch_id,
@@ -1226,8 +1219,6 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
         ):
             return
 
-        if not hasattr(self, "_scrape_batches"):
-            self._scrape_batches = {}
         target_diritem = transferinfo.target_diritem
         target_files = transferinfo.file_list_new or []
         target_key = (target_diritem.storage, target_diritem.path)
@@ -1264,8 +1255,6 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
         """
         if not task or not task.transfer_batch_id:
             return
-        if not hasattr(self, "_scrape_batches"):
-            self._scrape_batches = {}
         with job_lock:
             batch = self._scrape_batches.get(task.transfer_batch_id)
             if not batch:
@@ -1279,8 +1268,6 @@ class TransferChain(ChainBase, ConfigReloadMixin, metaclass=Singleton):
         """
         if not batch_id:
             return
-        if not hasattr(self, "_scrape_batches"):
-            self._scrape_batches = {}
 
         with job_lock:
             batch = self._scrape_batches.get(batch_id)
diff --git a/tests/test_transfer_job_manager.py b/tests/test_transfer_job_manager.py
index e032936e..fb05a5bc 100644
--- a/tests/test_transfer_job_manager.py
+++ b/tests/test_transfer_job_manager.py
@@ -2,6 +2,7 @@ import unittest
 from types import SimpleNamespace
 from unittest.mock import patch, MagicMock
 
+from app.core.config import settings
 from app.chain.transfer import JobManager, TransferChain
 from app.schemas import FileItem, TransferInfo, TransferTask
 from app.schemas.types import EventType, MediaType
@@ -86,6 +87,20 @@ def make_task(episode: int, season: int = 1) -> TransferTask:
     )
 
 
+def make_transfer_chain() -> TransferChain:
+    chain = object.__new__(TransferChain)
+    chain.jobview = JobManager()
+    chain._media_exts = settings.RMT_MEDIAEXT
+    chain._subtitle_exts = settings.RMT_SUBEXT
+    chain._audio_exts = settings.RMT_AUDIOEXT
+    chain._allowed_exts = (
+        chain._media_exts + chain._audio_exts + chain._subtitle_exts
+    )
+    chain._success_target_files = {}
+    chain._scrape_batches = {}
+    return chain
+
+
 def migrate_to_media_job(jobview: JobManager, task: TransferTask):
     task.mediainfo = FakeMedia()
     jobview.migrate_task(task)
@@ -192,8 +207,7 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual(task2.fileitem, jobs[0].tasks[0].fileitem)
 
     def test_exception_failure_does_not_mark_downloader_without_history(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
+        chain = make_transfer_chain()
         completed = []
 
         def fake_transfer_completed(hashs, downloader):
@@ -212,8 +226,7 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual([], chain.jobview.list_jobs())
 
     def test_successful_history_skip_marks_downloader_hash_completed(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
+        chain = make_transfer_chain()
         completed = []
 
         def fake_transfer_completed(hashs, downloader):
@@ -255,8 +268,7 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual([("abc123", "qbittorrent")], completed)
 
     def test_failed_history_skip_still_marks_downloader_hash_completed(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
+        chain = make_transfer_chain()
         completed = []
 
         def fake_transfer_completed(hashs, downloader):
@@ -298,10 +310,8 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual([("abc123", "qbittorrent")], completed)
 
     def test_unrecognized_task_marks_downloader_hash_completed(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
+        chain = make_transfer_chain()
         chain.post_message = lambda *_args, **_kwargs: None
-        chain._scrape_batches = {}
         completed = []
 
         def fake_transfer_completed(hashs, downloader):
@@ -336,10 +346,7 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual([], chain.jobview.list_jobs())
 
     def test_scrape_event_is_aggregated_by_transfer_batch_across_seasons(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
-        chain._success_target_files = {}
-        chain._scrape_batches = {}
+        chain = make_transfer_chain()
         chain.eventmanager = MagicMock()
         chain.transfer_completed = lambda *args, **kwargs: None
 
@@ -430,10 +437,7 @@ class TransferJobManagerTest(unittest.TestCase):
         self.assertEqual({}, chain._scrape_batches)
 
     def test_scrape_event_keeps_immediate_behavior_without_transfer_batch(self):
-        chain = object.__new__(TransferChain)
-        chain.jobview = JobManager()
-        chain._success_target_files = {}
-        chain._scrape_batches = {}
+        chain = make_transfer_chain()
         chain.eventmanager = MagicMock()
         chain.transfer_completed = lambda *args, **kwargs: None